Hybrid coating

Abstract

Method for providing an at least two-component material composite (10) for a vacuum application, by providing a metallic support body (1), forming a metal-oxide layer (2) on the surface of the metallic support body (1) by anodizing and providing an anodized surface (3), the metal-oxide layer (2) comprises a plurality of depressions (4) each of which having an opening at the anodized surface (3) and extending from the anodized surface (3) into the metal-oxide layer (2), and covering the anodized surface (3) to increase resistance of the anodized surface (3). The metal-oxide layer (2) is formed to provide the plurality of depressions (4) with defined depths and widths, wherein the depressions are formed with defined distance to each other, and covering the anodized surface (3) comprises applying a compound layer deposition technique with depositing a defined number of layers of a metal compound (6) on the metal-oxide layer (2), and, by that, providing a metal compound layer (6) of defined thickness on the anodized surface (3) and successively filling the plurality of depressions (4) at least partly with the metal compound (6).

Description

HYBRID COATINGFIELD OF INVENTION

[0001] The invention relates to a method which provides manufacturing of an at least two-component material composite for a vacuum application and to a respective vacuum component which comprises said two-component material composite.BACKGROUND OF THE INVENTION

[0002] In many fields of industrial applications the use of proper basic material to manufacture devices and parts thereof is a critical issue. Depending on the application, the basic material does have to provide specific properties like chemical or physical resistance, light weight, flexibility etc. This is in particular true for applications under vacuum conditions, especially in combination with deposition or etching processes.

[0003] As for example, key components of a vacuum processing chamber can be built from standard aluminum alloys. To further improve durability and robustness of the components the used alloy, i.e. at least its surface, is preferably hardened. Hardening can be provided by different processes. One hardening process often used in this context is an anodic coating process. Such anodizing can increase resistance to corrosion and wear, and can provide better adhesion for particular coatings like paint or polymers. The anodic coatings are most commonly applied to protect aluminum alloys, although processes also exist for titanium, zinc, magnesium, niobium, zirconium, hafnium, and tantalum.

[0004] Anodizing changes the microscopic texture of the surface and the crystal structure of the metal near the surface. The coatings can typically be porous, so a successive sealing process is often needed to achieve corrosion resistance. Anodized aluminum surfaces, for example, are harder than the underlaying aluminum but provide low to moderate wear resistance that can be improved with increasing thickness or by applying suitable sealing substances. The anodiccoating or film is generally much stronger and more adherent than most types of paint and metal plating, but also more brittle. This makes them less likely to crack and peel from ageing and wear, but more susceptible to cracking e.g. from thermal stress.

[0005] Sealing of the anodic coating can for example be done either through hydro-thermal sealing or precipitating sealing, to reduce porosity and interstitial pathways that allow corrosive ion exchange between the surface and the substrate. Precipitating seals enhance chemical stability but are less effective in eliminating ionic exchange pathways. Hydro-thermal sealing can be performed by dipping the anodized aluminum surface into heated water to provide generation of aluminum hydroxide to close the surface pores.

[0006] Sealing is the final step in the anodizing process and can be performed by e.g. long immersion in boiling-hot (e.g. 96-100°C) deionized water or steam. Here, the oxide is converted into its hydrated form and the resulting swelling reduces the porosity of the surface. Further, a mid-temperature sealing process can be applied which works at 70-80°C in solutions containing organic additives and metal salts. Also, cold sealing processes are available, where the pores are closed by impregnation of a sealant in a room-temperature bath.

[0007] A drawback of typical sealing processes is that the additionally formed aluminum hydroxide is less robust and less wear resistant compared to the underlaying aluminum oxide layer. Further, the surface remains still brittle, in particular when loads are applied on the surface, e.g. caused by pressure arising when pressing a valve closure onto the valve seat. The upper layer(s) of the surface will typically be worn away due to the loads.

[0008] As a result, gas pathways in the material and material particles may be generated which both lead to improper material characteristics or properties. Hence, resulting problems are possible contaminations and undefined outgassing in the course of substrate processing cycles to be driven with a respective processing chamber. Such deviations lead to different and improper product quality, e.g. different substrate surface conditions.OBJECT OF THE INVENTION

[0009] It is therefore the object of the invention to provide an improved method or material composite which overcomes above-mentioned drawbacks.

[0010] In particular, it is an object of the invention to provide an improved method to manufacture material composites for vacuum applications which provide improved resistance and robustness.

[0011] These objects are solved by implementing the characterizing features of the independent claims. Features which further develop the invention in alternative or advantageous manner can be deduced from the dependent patent claims.SUMMARY OF THE INVENTION

[0012] The invention relates to an approach for conditioning, hardening or finishing a work piece to provide an improved work piece for e.g. vacuum applications. One general idea of the invention is to use a base substrate (herein also called: metallic support body) and to first form an anodized layer on the base substrate by anodizing. Such layer may preferably comprise or be formed of a metal oxide. As outlined above, anodizing a substrate is a well-known technique to improve, e.g., robustness of a surface and / or to harden a work piece.

[0013] In a subsequent step, the anodized layer is coated and by that a hybrid coating (related to two different coating approaches combined) is provided. Such coating is performed by applying a compound layer deposition (herein also: CLD) technique. Such compound layer deposition technique can be at least one of atomic layer deposit (ALD) and molecular layer deposition (MLD). A metal compound is used for the CLD process which results in filling of depression, which are formed by anodizing, and covering the anodized layer with the metal compound.

[0014] As a result, the surface of the base substrate is covered by an at least two-component material composite which provides improved robustness, wear and corrosion resistance. Further, by adjusting the shapes and / or dimensions of the depressions and / or by choosing a proper metal compound for coating, thermaland / or electrical conductivity of the whole work piece can be improved or even thermal isolation can be provided. Respective variations are described in more detail below.

[0015] Accordingly, the invention relates to a method for providing an at least two-component material composite for a vacuum application. The method comprises providing a metallic support body and forming a metal-oxide layer on the surface of the metallic support body by anodizing. By that, an anodized surface is provided. The metal-oxide layer is formed to comprise a plurality of depressions each of which has an opening at the anodized surface and extends from the anodized surface into the metal-oxide layer.

[0016] The anodized surface is covered to, e.g., increase resistance of the anodized surface.

[0017] The metal-oxide layer is formed to provide the plurality of depressions with defined depths and widths, wherein the depressions are formed with defined average distance to each other.

[0018] For covering the anodized surface, a compound layer deposition (CLD) technique is applied. The CLD technique comprises depositing a defined number of layers of a metal compound on the metal-oxide layer, and, by that, providing a metal compound layer of defined thickness on the anodized surface and successively (gradually, layer-by-layer) filling the plurality of depressions at least partly with the metal compound.

[0019] General advantages of this method are that the resulting mechanical stability, robustness, durability and also chemical resistance of the work piece can be improved significantly, in particular when compared to sealing or coating processes of anodized layers of the prior art.

[0020] In one embodiment, applying the compound layer deposition technique can comprise at least one of applying atomic layer deposition (ALD) and depositing a defined number of atomic layers, and applying molecular layer deposition (MLD) and depositing a defined number of molecular layers. Both these techniques can provide to gradually grow a compound on the metal-oxide layer in a layer-by-layermanner. By that, i.e. by defining the number of layer deposition cycles to be performed, a defined thickness of the compound layer can be adjusted.

[0021] In one embodiment, the metallic support body can comprise aluminum or is formed of an aluminum alloy. Aluminum is one of the typically used materials for constructing components for vacuum applications. However, the alloy itself often provides properties which initially are not sufficient for vacuum applications and have to be improved.

[0022] In one embodiment, the metal compound can comprise at least one of metal oxide, metal fluoride, metal nitride, metal carbide, metal sulfide, metal phosphide, zinc oxide, titanium oxide, titanium nitride, yttrium oxide, yttrium fluoride, yttrium oxyfluoride, aluminum and yttrium.

[0023] In one embodiment, at least one of the plurality of depressions can comprise a cylindrical shape. The depressions can be formed to have proper shapes. Such shaping of the depressions can be done by respective controlling of processing parameters which are applied while anodization of the substrate is conducted. Preferred controlling parameters can be an applied current, temperature and / or concentration of an electrolytic solution used for anodizing.

[0024] In one embodiment, at least one of the plurality of depressions can comprise a cup-like or bowl-like shape.

[0025] The above mentioned shapes of the depressions can facilitate to fill the depressions by means of the CLD process up to 100%. By that, the surface of the workpiece can be improved with respect to resistances mentioned above. Further, due to the high filling rate, the composite can provide increased thermal and electric conductivity. This is because the metal compound applied by CLD can extend from the surface through almost the entire metal-oxide layer and can further extend to the metallic support body. In other words: the deposited compound can provide to bridge the metal-oxide barrier and by that to improve conductivity.

[0026] According to an embodiment, at least one of the plurality of depressions can be formed so that the at least one depression comprises a defined shape, wherein its width at the anodized surface of the at least one depression is smallerthan its width at half the depth of the at least one depression. In other words, at least a part of the depression in the inner volume can be wider than the depression at the surface.

[0027] In one embodiment, at least one depression of the plurality of depressions can comprise a bottle-like shape. Such type of depression can comprise a region closer to the surface (herein also called: bottleneck) which comprises a diameter which is smaller than the diameter of the depression closer to the metallic support body.

[0028] In particular all or the majority of the depressions can be formed like this.

[0029] In one embodiment, the width of the at least one of the depressions at half the depth of the at least one depression can be between 1.5 to 20 times bigger than the width of the at least one depression at the anodized surface.

[0030] In one embodiment, a void can be formed inside of the at least one depression by layer-by-layer deposition of the metal compound layer at the inner wall of the at least one depression, and by closing the at least one depression by layer-by-layer deposition of the metal compound before the inner volume of the at least one depression is (totally) filled by the metal compound.

[0031] Such forming of a void in the depression can preferably be provided with depressions comprising a bottle-like shape. Here, the metal compound is deposited layer-by-layer also at the inner surface of the depressions and also at the bottleneck simultaneously. This results in a closing of the bottleneck by total filling the bottleneck with the metal compound before the entire volume deeper in the depression is filled with the compound. The inner volume is blocked by the closed bottleneck before it can totally be filled.

[0032] This approach provides to encapsulate a plurality of voids in a plurality of depressions in a surface region of a work piece. Due to the technical characteristics of a used deposition method, the generated voids comprise (very) low-density or even vacuum conditions in their volumes. This results in increased (thermal) isolating characteristics of the depressions and of the at least two-component material composite, and in particular also of the entire work piece.

[0033] In one embodiment, covering the anodized surface can comprise providing a metal compound layer of defined thickness at an inner wall (surface) of the depressions. This means that deposition of the compound layer at the surface of the depressions comes along with the layer deposit at the anodized surface.

[0034] In an embodiment, the compound can comprise a material which provides electric conductivity oc, wherein the electric conductivity oc is greater than the electric conductivity of the metal-oxide layer OM, in particular three to ten times greater.

[0035] In particular, oc > 106S / m, in particular wherein the compound comprises doped zinc oxide, in particular bromine-doped zinc oxide.

[0036] By that, the electric conductivity of the composite can be increased significantly which results in a respectively increased overall electric conductivity of a work piece which comprises the composite.

[0037] In one embodiment, the compound can comprise a material which provides electric conductivity oc, wherein the electric conductivity oc is smaller than the electric conductivity of the metal-oxide layer OM. By coating the oxide layer with low-conductive material the isolating properties of the entire composite can be improved.

[0038] The invention also relates to an at least two-component material composite which comprises a metallic support body and a metal-oxide layer on the surface of the metallic support body. The metal-oxide layer provides an anodized surface and comprises a plurality of depressions of defined depths and widths each of which having an opening at the anodized surface and extending from the anodized surface into the metal-oxide layer. The depressions are formed with defined average distance to each other.

[0039] Further, a defined number of layers of a metal compound is provided on the metal-oxide layer. The defined number of layers of a metal compound is built by a compound layer deposition technique. The number of layers provide a metal compound layer of defined thickness on the anodized surface, and an at least partly filling of the plurality of depressions with the metal compound.

[0040] The invention also relates to a closure element for a vacuum valve, having a first sealing surface which corresponds to a second sealing surface of a valve opening, in particular with regard to shape and size, wherein the second sealing surface runs around the vacuum valve opening. The first sealing surface comprises a two-component material composite according to above and the two-component material composite provides a metal carrier. A sealing material is applied to the metal carrier along a sealing surface course, in particular is vulcanized onto the latter, with a defined profile, in particular with a defined height in the direction of the surface normal of the metal carrier.

[0041] The invention also relates to an at least two-component material composite obtained by carrying out a method of above.BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The apparatus according to the invention and the method according to the invention are described in detail hereinafter merely as an example with reference to specific exemplary embodiments shown schematically in the drawings, wherein further advantages of the invention are also discussed. In detail in the figures:

[0043] figures 1a to 1c schematically show an embodiment of manufacturing steps of a method according to the invention and a two-component material composite formed according to the invention;

[0044] figure 2 shows a further embodiment of an at least two-component material composite according to the invention;

[0045] figure 3 shows an embodiment of a vacuum processing system which comprises an at least two-component material composite according to the invention;

[0046] figures 4a to 4c show an embodiment of a vacuum valve which comprises a valve closure having an at least two-component material composite according to the invention; and

[0047] figure 5 shows the steps of a method to provide an at least two-component material composite according to the invention.DETAILED DESCRIPTION OF THE DRAWINGS

[0048] Figures 1a-1c show schematically an embodiment of manufacturing steps of a method according to the invention and a two-component material composite 10 according to the invention.

[0049] First, as can be seen in figure 1a, a metallic support body 1 is provided. In the shown embodiment, the metallic support body 1 comprises aluminum and is preferably provided as an aluminum alloy.

[0050] On the surface of the metallic support body 1 a metal-oxide layer 2 is formed (figure 1b). The metal-oxide layer 2 comprises aluminum and is preferably made of aluminum oxide. The metal-oxide layer 2 is formed by anodizing and provides an anodized surface 3.

[0051] The anodized aluminum layer 2 can be created by passing a direct current through an electrolytic solution, with the aluminum object (metallic support body 1 ) serving as the anode. The current releases hydrogen at the cathode (the negative electrode) and oxygen at the surface of the aluminum anode, creating a build-up of aluminum oxide. Alternating the current and pulsed current is also possible. As for example, the voltage required by various solutions may range from 1 to 300 V DC, although most fall in the range of 15 to 21 V. Higher voltages are typically required for thicker coatings formed in sulfuric and organic acid. The anodizing current varies with the area of aluminum being anodized and typically ranges from 30 to 300 A / m2

[0052] The metal-oxide layer 2 comprises a plurality of depressions 4 each of which has an opening 5 at the anodized surface 3 and extends from the anodized surface into the metal-oxide layer 2.

[0053] Aluminum anodizing can be performed in an acidic solution, e.g. sulfuric acid or chromic acid, which slowly dissolves the aluminum oxide. The acid action can be balanced with the oxidation rate to form a coating with such depressions4, i.e. with also called nano-pores. The depressions can be built with 10 nm to 150 nm in diameter.

[0054] The depressions 4 allow the electrolyte solution and current to reach the aluminum substrate (metallic support body 1) and continue growing the coating to greater thickness beyond what is produced by auto-passivation. Anodizing conditions such as electrolyte concentration, acidity, solution temperature, and current must be controlled to allow the formation of a consistent oxide layer 2. Harder, thicker films tend to be produced by more concentrated solutions at lower temperatures with higher voltages and currents. By that, the film thickness can by adjusted to range from under 1 pm up to 150 pm.

[0055] In other words, the depressions 4 can be formed with defined depths t and widths. Further, the depressions 4 can be formed with defined average distance to each other.

[0056] In the shown embodiment, the diameter d of at least one of the depressions 4 is in a range between 10 nm and 100 nm at the opening 5 of the depression. In particular, the diameter d basically of all the depressions 4 is between 10 nm and 100 nm. In another embodiment, the diameter d can be between 5 nm and 200 nm.

[0057] An average distance x between two neighboring depressions can vary according to the respective diameters, e.g. the distance x is equal to, double or ten times the diameter d. It is to be understood that the average distance can be related to an average of the distances between multiple (neighboring) depressions. The distance can be measured from center to center of the depressions or from border to border of the depressions.

[0058] In other words, the aluminum component undergoes an anodic coating process, resulting in the formation of tailored pores (depressions 4). The dimensions of these pores - specifically pore width, depth, and wall thickness -can be adjusted based on the application requirements.

[0059] Figure 1c shows the result of applying a compound layer deposition (here also called: CLD) technique to cover the anodized surface 3. Here, atomic layer deposition (ALD) is used as compound layer deposition technique. Byperforming ALD, the depressions 4 are filled layer-by-layer with a particular compound 6. Further, a defined number of layers of the compound is deposited on the metal-oxide layer 2, in particular on the anodized surface 3. Hence, a layer of defined thickness can be provided on the anodized surface 3.

[0060] Atomic layer deposition (ALD) is a thin-film deposition technique based on the sequential use of a gas-phase chemical process. ALD reactions can make use of two chemicals called precursors (also called "reactants"). These precursors react with the surface of a material one at a time in a sequential, self-limiting, manner. A thin film can slowly be deposited through repeated exposure to separate precursors. Consequently, the maximum amount of material deposited on the surface after a single exposure to all of the precursors (a so-called ALD cycle) is determined by the nature of the precursor-surface interaction. By varying the number of cycles it is possible to grow materials uniformly and with high precision on arbitrarily complex and large substrates.

[0061] A sister technique of atomic layer deposition (ALD), molecular layer deposition (MLD), uses organic precursors to deposit polymers. By combining the ALD / MLD techniques, it is possible to apply highly conformal and pure hybrid films.

[0062] Applying the CLD process provides forming of each layer along the boundary surface of the metal-oxide layer 2, i.e. the layers are simultaneously formed on top of the metal-oxide layer 2 and on the walls (and bottom) of the depressions 4. As a result, the depressions 4 can be filled entirely and also a protective layer can be formed on top of the metal-oxide layer 2.

[0063] The compound 6 is a metal compound. In the present embodiment, the compound comprises zinc oxide.

[0064] An ALD process, can utilize other materials such as aluminum oxide, yttrium oxide, yttrium fluoride, or combinations thereof. As mentioned, the process can effectively fill the pores 4. A filling ratio of up to 100% is achievable. The resulting material within the pores exhibits high quality and density.

[0065] The combination of forming a metal-oxide layer 2 and covering the anodized surface 3 by applying compound layer deposition provides improved corrosion resistance. A factor of 10 or greater concerning improvement incorrosion resistance can be realized. Hence, the concept can significantly extend the lifespan of coated components in aggressive environments.

[0066] Further, a reduction of possible outgassing can be provided. Compared to typical hard anodic coatings, this concept mitigates outgassing. This is crucial in vacuum applications where outgassing can negatively impact vacuum systems or sensitive equipment or even a substrate to be produced.

[0067] Moreover, cleanliness can be improved. The CLD protective coating can enhance overall cleanliness levels and, thus, meets the stringent requirements of the semiconductor industry (including display and solar applications). Reduced contamination is essential for optimal vacuum performance.

[0068] Alos, the generation of particles can be reduced by the proposed approach. This leads to robust and reliable cleanroom environments where even tiny particles can affect yield and product quality.

[0069] In summary, the concept according to the invention addresses and improves corrosion, outgassing, cleanliness, and particle-related challenges.

[0070] Due to using e.g. zinc oxide as the filling and covering compound, mechanical stability (wear resistance) of the upper surface of the at least two-component material composite 10 (comprising at least the anodized metal-oxide layer 2 and the deposited compound 6) is improved compared to conventional sealing processes. Plasma resistance is improved respectively, which is a crucial requirement in context of vacuum applications.

[0071] A further advantage of the approach according to figures 1a to 1c is that electrical conductivity of the composite 10 can be improved, i.e. increased compared to conventionally anodized and sealed composites. The material or compound used with the deposition process can provide increased conductivity performance and by that results in an increased overall conductivity of the composite 10. This is true also because of the almost direct contact (or a comparatively thin intermediate layer) between the CLD applied compound 6 and the metallic support body 1.

[0072] This improved electrical conductivity provides better performances in context of please applications. As for example, a surface of a chuck which is formed according to the invention can prevent charging of a substrate which is hold by the chuck during plasma processing.

[0073] Since thermal conductivity of a compound often goes along with electrical conductivity, the above-said is also true for thermal or heat dissipation from a substrate to be processed.

[0074] Figure 2 shows a further embodiment of an at least two-component material composite 10 according to the invention.

[0075] The material composite 10 comprises a metallic support body 1 which is made from an aluminum alloy. Further, the composite 10 comprises a metal-oxide layer 2 on the surface of the metallic support body. The metal-oxide layer 2 provides an anodized surface 3 and comprises a plurality of depressions 4 of defined depths t and widths d each of which having an opening 5 at the anodized surface and extending from the anodized surface into the metal-oxide layer 2. The depressions 4 are formed with defined distance to each other.

[0076] In contrast to the embodiment according to figure 1c, the depressions 4 are formed with different, specific shapes. In the present embodiment, the widths of the depressions 4 at the anodized surface are smaller than their widths at half the depths of the depressions.

[0077] In particular, as shown here, the depressions 4 are formed to have a bottle-like shape. Such shape can be provided by respectively controlling and adjusting the anodizing parameters described above during the anodizing cycle.

[0078] Near the surface, regular (e.g. cylindrical) pores 4 with smaller diameters are formed, while deeper within the substrate the pores 4 comprise significantly larger diameters, e.g. up to 2, 20 or 50 times bigger.

[0079] In a process step after anodizing, a defined number of atomic layers of a metal compound 6 is built on the metal-oxide layer 2 by CLD technique, the number of atomic layers provide the metal compound layer of defined thickness on the anodized surface.

[0080] In the course of CLD, the metal compound is simultaneously also formed layer-by-layer at the inner walls of the depression and also in the region of the bottlenecks 7. As a result of layer-by-layer deposition the bottlenecks 7 of the depressions 4 are filled before the entire inner volume of the depressions 4 can be filled. By that, a void 8 is formed inside of each of the depressions 4.

[0081] Since the CLD process is performed under vacuum conditions, the voids here 8 can be considered to be evacuated (contain vacuum).

[0082] According to other embodiments, the voids 8 may contain a filling gas like helium which can be introduced during or because of the technical characteristics of the used CLD process. A fluid (e.g. gas) inside of the voids 8 preferably comprises low density.

[0083] In other words: in the CLD (e.g. ALD) coating step, the small pores (bottlenecks) at the sample surface are sealed, leaving the larger pores 4 below unfilled. These larger pores can contain either low-density material or vacuum.

[0084] Since the voids 8 comprise vacuum, significantly improved thermal isolation of the material composite 10 is provided. The enclosed vacuum voids 8 prevent thermal conductivity of the whole composite. That effect is advantageous in case of processing applications which cause high temperatures and heat dissipation or transportations of other system components should be prevented.

[0085] Hence, improved electrical and thermal resistance can be provided by forming of a (thin) layer of protective coating according to the invention. The composite further meets stringent high-vacuum requirements while allowing spatial control over thermal and electrical flows on highly conductive aluminum substrates.

[0086] Further advantageous effects like mechanical robustness, improved corrosion resistance, reduced outgassing, improved cleanliness, and less particle generation are provided accordingly as described above.

[0087] As for example, in case when using a material composite 10 according to figure 2 for plasma or other high temperature applications cooling efforts of the system or of a support of the plasma device (e.g. chuck) can be reduced.

[0088] A further advantage of an embodiment according to figure 2 is related to material stress. A conventional anodizing and sealing processes, i.e. forming an anodized layer of typically metal oxide and successively sealing the pores and surface layer by typically converting a part of the meatal oxide into its hydrated form, introduced inner material stress in the formed layer. This is because the oxide or hydroxide form of the metal requires more space than the metal in the alloy does. Hence, (at least lateral) stress is introduced by anodizing.

[0089] This stress results in less mechanical resistance, in particular at the surface, and increases the probability of surface cracking due to loads applied to the composite. The composite system becomes more brittle.

[0090] When forming the voids 8 according to the invention, these voids 8 can provide to absorb lateral but also normal stress due to their inner volumes which comprise low density fluids or even vacuum. Hence, the voids 8 provide flexible elements in the dynamic composite system and can act like buffers of dampers which can be squeezed. This results in more overall flexibility and increases mechanical stability.

[0091] Figure 3 shows an embodiment of a vacuum processing system 20 which comprises an at least two-component material composite 10 according to the invention.

[0092] The system 20 comprises a vacuum process chamber 21. The process chamber 21 is configured and designed to receive a substrate or work piece to be processed, e.g. by means of an automated transportation system like a robot. The substrate is brought into the vacuum chamber 21, a defined processing step is performed and, afterward, the processed substrate is taken out of the vacuum chamber 21.

[0093] The system 20 also comprises a downstream unit 22 which is connected to the vacuum chamber 21. The downstream unit 22 is arranged and connected to the vacuum volume 21 to regulate a gas pressure inside of the vacuum volume 21. According to this embodiment, the downstream unit 22 comprises a vacuum pump 23 and a vacuum regulation valve 24. The vacuum pump 23 and / or the vacuum regulation valve 24 are designed as controllable components, whichmeans that an actual suction output of the vacuum pump 23 and / or an actual cross section of a valve opening are variable upon applying a respective controlling signal. By such regulation a rate of fluid outflow out of the vacuum chamber 21 and cavity pressure can be varied and set.

[0094] Furthermore, the system 20 comprises a set of controllable inlet valves (here: three) which build a fluid application arrangement 30. The fluid application arrangement 30 is connected to the vacuum chamber 21 and configured to provide inflow of at least one fluid into the vacuum chamber 21 in controlled manner. In this embodiment the fluid application arrangement 30 is configured for controlling the application of three different fluids, in particular of three different precursors. Each of the inlet valves can be controlled individually, e.g. can be controlled to inject a respective precursor in pulsed manner for a defined time period.

[0095] A precursor may be gas or vapors of material which are carried by a carrier gas. Hence, in context or the present invention, a precursor is to be understood to be a fluid.

[0096] A controlling and / or regulating unit 40 is also provided. The controlling and / or regulating unit 40 is connected to the controllable fluid application arrangement 30 and to the downstream unit 22. By that, the amount of defined precursors which flow into the vacuum chamber 21 and defined points in time during a processing cycle for such inflow can be controlled. The vacuum pressure inside of the vacuum volume 21 can be controlled as well.

[0097] To receive a substrate or work piece to be processed, the chamber 21 comprises an electrostatic chuck. The chuck comprises a support element 10 which is arranged to receive the substrate to be processed. The support element is provided as an at least two-component material composite 10 according to the invention.

[0098] Figures 4a-4c show an embodiment of a vacuum valve 50 which comprises a valve closure 51 having an at least two-component material composite 10 according to the invention.

[0099] The vacuum valve 50 is designed as a vacuum transfer valve 1 and is shown in different opening states.

[0100] The vacuum valve 50 has a rectangular, plate-shaped valve closure 51 (valve disk), which has a sealing element 52 for gas-tight closure of a valve opening 53. The opening 53 has a cross-section corresponding to the valve closure 51 and is formed in a wall of the valve housing 54. This wall can, for example, be the wall of a vacuum process chamber. The opening 53 is surrounded by a valve seat, which in turn provides a sealing surface 55 corresponding to the sealing element 52 of the valve closure 51. The sealing element 52 of the valve closure 51 runs around the valve closure 51. In a closed position S (Fig. 4c), the seal is pressed between the valve closure 51 and the sealing surface 55.

[0101] The opening 53 connects a first gas region L, which is located to the left of the wall 54, with a second gas region R to the right of the wall 54. The wall 54 is formed, for example, by a chamber wall of a vacuum chamber. The vacuum valve 50 is then formed by interaction between the chamber wall 54 and the valve closure 51.

[0102] It is understood that the valve seat together with the sealing surface 55 can alternatively be designed as a valve component structurally fixed to the valve 50 and can, for example, be arranged, e.g. screwed, to a chamber opening.

[0103] As shown here, the valve closure 51 can be arranged on an adjustment arm 56, which here is rod-shaped, for example, and extends along a geometric adjustment axis V. The adjustment arm 56 is mechanically coupled to a drive unit 57, by means of which the valve closure 51 in the first gas region L to the left of the wall 54 can be adjusted between an open position O (Fig. 4a) via an intermediate position Z (Fig. 4b) into a closed position S (Fig. 4c) by adjusting the adjustment arm 56 by means of the drive unit 57.

[0104] In the open position O, the valve closure 51 is located outside a projection area of the opening 53 and releases it completely, as shown in Fig. 4a.

[0105] By linear adjustment of the valve closure 51 in the axial direction in a plane parallel to or coaxial with the adjustment axis V and parallel to the wall 54, the valve closure 51 can be adjusted from the open position O to the intermediate position Z by means of the drive unit 57.

[0106] In this intermediate position Z (Fig. 4b), the sealing element 52 of the valve closure 51 is located at a distance opposite the sealing surface 55 of the valve seat surrounding the opening 53.

[0107] By adjusting in the direction of the opening axis C defined by the opening 53 (here: transverse to the adjustment axis V), e.g. perpendicular to the wall 54 and the valve seat, the valve closure 51 can be adjusted from the intermediate position Z to the closed position S (Fig. 4c).

[0108] In the closed position S, the valve disk 51 closes the opening 53 in a gastight manner and separates the first gas region L from the second gas region R in a gas-tight manner.

[0109] The vacuum valve is opened and closed by means of the drive unit 57, in this case by an L-shaped movement in two directions V and C of the valve closure 51, e.g. perpendicular to each other. The valve shown is therefore also called an L-type valve.

[0110] A transfer valve 50 as shown is typically used to seal a process volume (vacuum chamber) and to load and unload the volume. Frequent changes between the open position O and the closed position S are the rule in such an application.

[0111] The valve closure 51 comprises an at least two-component material composite 10 according to the embodiments of figures 1-2.

[0112] The two-component material composite 10 provides a metal carrier. The sealing material 52 is applied to the metal carrier along a sealing surface course. The sealing material 52 can be vulcanized onto the latter. The sealing material 52 comprises a defined profile, in particular with a defined height in the direction of the surface normal of the metal carrier.

[0113] In other words: the sealing material 52 is arranged on top of the layer-by-layer formed compound 6, wherein the compound 6 comprises a metallic material. By that, an improved mechanical robustness of the seal system can be provided due to the improved stability of the composite 10.

[0114] Figure 5 shows the steps of a method to provide an at least two-component material composite 10 according to the invention.

[0115] In a first step 61 , a metallic support body is provided to build the material composite 10 based on this support. The support body may be a metallic work piece to be formed to a component of a vacuum processing chamber. Such support body often does initially not meet the requirements for vacuum applications, which may e.g. be high wear and corrosion resistance. To meet these requirements, further hardening and finishing steps can be necessary.

[0116] In next step 62, metal-oxide layer with an anodized surface is formed on the surface of the metallic support body. This is done by anodizing the metallic support body. The metal-oxide layer comprises a plurality of depressions or pores. Such depressions result from the anodizing process. Each of the depressions has an opening at the anodized surface and extends from the anodized surface into the metal-oxide layer. The depressions are formed with defined depths and widths and have defined distance to each other. The parameters of depths, widths and distance can be adjusted by controlling the processing parameters of the anodizing process, like temperature, current and concentration of the used electrolyte.

[0117] Subsequently (step 63), the anodized surface is covered by applying a compound layer deposition (CLD) technique to, e.g., increase resistance of the anodized surface. For instance, atomic layer deposit (ALD) or molecular layer deposition (MLD) can be used as suitable compound layer deposition technique.

[0118] In the course of performing the CLD technique, a defined number of (atomic or molecular) layers of a (metal) compound is deposited on the metal-oxide layer. By that, a compound layer of defined thickness is provided on the anodized surface and the plurality of depressions are gradually (successively) filled at least partly with the compound.

[0119] It is understood that the depicted figures only schematically depict possible exemplary embodiments. The various approaches can according to the invention also be combined with one another and with prior art methods and devices for vacuum applications.

Claims

CLAIMS1. Method for providing an at least two-component material composite (10) for a vacuum application, by• providing a metallic support body (1 ),• forming a metal-oxide layer (2) on the surface of the metallic support body (1) by anodizing and providing an anodized surface (3), the metal- oxide layer (2) comprises a plurality of depressions (4) each of which having an opening (5) at the anodized surface (3) and extending from the anodized surface (3) into the metal-oxide layer (2), and• covering the anodized surface (3) to increase resistance of the anodized surface (3),characterized in that• the metal-oxide layer (2) is formed to provide the plurality of depressions (4) with defined depths (t) and widths (d), wherein the depressions are formed with defined average distance (x) to each other, and• covering the anodized surface (3) comprises applying a compound layer deposition technique with° depositing a defined number of layers of a metal compound (6) on the metal-oxide layer (2), and, by that,° providing a metal compound layer (6) of defined thickness on the anodized surface (3) and° successively filling the plurality of depressions (4) at least partly with the metal compound (6).

2. Method according to claim 1, whereinapplying the compound layer deposition technique comprises at least one of• applying atomic layer deposition (ALD) and depositing a defined number of atomic layers, and• applying molecular layer deposition (MLD) and depositing a defined number of molecular layers.

3. Method according to claim 1 or 2, whereinthe metallic support body (1 )• comprises aluminum or• is formed of an aluminum alloy.

4. Method according to any of the preceding claims, whereinthe metal compound (6) comprises at least one of metal oxide, metal fluoride, metal nitride, metal carbide, metal sulfide, metal phosphide, zinc oxide, titanium oxide, titanium nitride, yttrium oxide, yttrium fluoride, yttrium oxyfluoride, aluminum and yttrium.

5. Method according to any of the preceding claims, whereinat least one of the plurality of depressions (4) comprises at least one of a cylindrical shape, a cup-like shape and a bowl-like shape.

6. Method according to any of the preceding claims, whereinat least one of the plurality of depressions (4) is formed so that the at least one depression (4) comprises a defined shape, wherein the width (d) at the anodized surface (3) of the at least one depression (4) is smaller than its width at half the depth (t) of the at least one depression (4).

7. Method according to claim 6, wherein• the at least one depression (4) of the plurality of depressions comprises a bottle-like shape, or• the width of the at least one depression increases with increasing depth.

8. Method according to any of the claims 6 or 7, whereinthe width (d) of the at least one of the depressions (4) at half the depth (t) of the at least one depression is between 1.5 to 20 times bigger than the width (d) of the at least one depression at the anodized surface (3).

9. Method according to any of the claims 6 to89, whereina void (8) is formed inside of the at least one depression (4) by• layer-by-layer deposition of the metal compound layer (6) at the inner wall of the at least one depression (4), and• closing the at least one depression (4) by layer-by-layer deposition of the metal compound, wherein closing is provided before the inner volume of the at least one depression is filled by the metal compound.

10. Method according to any of the preceding claims, whereinthe compound comprises a material which provides electric conductivity oc, wherein the electric conductivity oc is greater than the electric conductivity of the metal-oxide layer OM.

11. Method according to any of the claims 1 to 9, whereinthe compound comprises a material which provides electric conductivity oc, wherein the electric conductivity oc is smaller than the electric conductivity of the metal-oxide layer OM.

12. At least two-component material composite (10) comprising• a metallic support body (1 ),• a metal-oxide layer (2) on the surface of the metallic support body (2) providing an anodized surface (3), the metal-oxide layer (2) comprises a plurality of depressions (4) of defined depths and widths each of which having an opening (5) at the anodized surface and extending from the anodized surface into the metal-oxide layer (2), wherein the depressions (4) are formed with defined average distance to each other, and• a defined number of layers of a metal compound (6) on the metal-oxide layer (2) built by a compound layer deposition technique, the number of layers provide° a metal compound layer of defined thickness on the anodized surface (3), and° an at least partly filling of the plurality of depressions (4) with the metal compound (6).

13. At least two-component material according to claim 12, wherein• a void is formed inside of at least one of the depressions,• the void is surrounded by the metal compound, in particular by the metal compound layer provided by layer-by-layer deposition of the metal compound, and• the at least one depression is closed the by the metal compound, in particular by the metal compound layer provided by layer-by-layer deposition of the metal compound.

14. Closure element (51) for a vacuum valve (50), having a first sealing surface which corresponds to a second sealing surface (55) of a valve opening (53), wherein the second sealing surface (55) runs around the vacuum valve opening (53), wherein• the first sealing surface comprises a two-component material composite (10) according to claim 12 or 13 and the two-component material composite (10) provides a metal carrier, and• a sealing material (52) is applied to the metal carrier along a sealing surface course with a defined profile.

15. At least two-component material composite obtained by carrying out a method according to any one of claims 1 to 12.

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